Stereoselective [3+2] Carbocyclization of Indole-Derived Imines and Electron-Rich Alkenes: A Divergent Synthesis of Cyclopenta[<i>b</i>]indole or Tetrahydroquinoline Derivatives
作者:Alicia Galván、Jonás Calleja、Adán B. González-Pérez、Rosana Álvarez、Angel R. de Lera、Francisco J. Fañanás、Félix Rodríguez
DOI:10.1002/chem.201503044
日期:2015.11.16
[3+2] carbocyclization reaction of indole‐2‐carboxaldehydes, anilines, and electron‐rich alkenes to obtain cyclopenta[b]indoles is disclosed. This pathway is different from the well‐established Povarov reaction: the formal [4+2] cycloaddition involving the same components, which affords tetrahydroquinolines. Moreover, by simply changing the Brønsted acid catalyst, this multicomponent coupling process could
公开了前所未有的吲哚-2-羧醛,苯胺和富电子烯烃的立体选择性[3 + 2]碳环化反应,以获得环戊[ b ]吲哚。该途径与公认的Povarov反应不同:正式的[4 + 2]环加成反应涉及相同的组分,产生四氢喹啉。此外,通过简单地改变布朗斯台德酸催化剂,该多组分偶联过程可以转向传统的Povarov途径生产四氢喹啉,或转向新的途径(抗-Povarov)以产生环戊四烯[ b]。]吲哚。在计算研究的支持下,提出了针对新的反Povarov反应的逐步Mannich / Friedel-Crafts级联反应,而针对Povarov反应提出了协同的[4 + 2]环加成机理。